QPP Data Resequencing for Parallel Turbo Decoding

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current interleaving methods in turbo coding, particularly in 3GPP standards, are computationally expensive and inefficient due to the reliance on division operations and sequential data processing, which hampers the decoding efficiency in wireless telecommunications.

Innovation Solution

The implementation of a Quadratic Permutation Polynomial (QPP) interleaving algorithm within a Field Programmable Gate Array (FPGA) that calculates the position for data items in the original order based on functions of the current position in the interleaved order, avoiding division operations and enabling parallel processing to shorten the data processing path.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional interleaving methods are used in turbo coding, then error dispersion capability is achieved, but computational complexity increases due to division operations

Engineering Contradiction:

Improveerror dispersion capabilityVSAvoidcomputational complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent transforms the QPP interleaving calculation from using division operations to using only multiplication and addition operations. Specifically, the patent derives that the interleaved position can be calculated as f(x) = (a*x + b*x^2) mod K using only multiplicative parameters a and b, eliminating the need for division operations while maintaining the same error dispersion capability.

Inventive Principle:

Principle #35Parameter changes

2Ease of operation

If sequential processing is used in interleaving, then implementation simplicity is maintained, but processing speed decreases

Engineering Contradiction:

Improveimplementation simplicityVSAvoidprocessing speed

Core Design Contradiction:

Ease of operationVSSpeed

Solution Approach 1:

The patent segments the interleaving calculation into independent parallel components. By expressing the interleaved position as separate calculations for the row index (i = (a*x + b*x^2) mod P) and column index (j = floor((a*x + b*x^2)/P)), the patent enables simultaneous computation of multiple interleaved positions without sequential dependencies, thereby achieving parallel processing capability.

Inventive Principle:

Principle #1Segmentation

3Measurement precision

If division operations are used in QPP interleaving, then position calculation accuracy is maintained, but processing delay increases

Engineering Contradiction:

Improveposition calculation accuracyVSAvoidprocessing delay

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent substitutes the mechanical division operation with equivalent multiplicative and additive operations. By using the relationship f(x) = (a*x + b*x^2) mod K and deriving i and j through multiplication and addition only, the patent eliminates time-consuming division operations while preserving the exact position calculation accuracy required for proper interleaving.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS8291291B1Data resequencing

Publication Date: 2012.10.16 ALTERA CORP

AI summary

Interleaving in which functions relating final and original positions are implemented with low complexity using inequalities based on the functions.